i have a 97 4.0L and mine does something similar where it will try to stall if i am coming to a stop or if i am already stopped and shifting from park into reverse or drive. However when it first starts up it idles at around 1000 rpm then slowly decreases, then once it warms up it starts having the problems.
Does the ZJ have a TPS? I thought it was mechanically connected but i may be wrong.
In any case I also do not know what the problem is. Some people have recommended that I do a tranny fluid change and try replacing the downstream 02 sensor. I am going to try these soon.
Stock 1997 ZJ Laredo